December 30, 2014

ABF and Other Stuff

Ho hum, just another outstanding LPOD image from the Minsk Miracle Imagers. They have a new telescope now that, in their hands, creates a work of art, with dramatic lighting, excellent composition and great tonality. Scientifically it's pretty interesting, too. With grazing illumination all the small bumps and hills are revealed, where not hidden by black spires of shadows. The floor of Archimedes is not featureless as it often appears, but peppered with craters less than about 2 km in diameter. To the right is the flooded edge of the nearly circular exposure of the Apennine Bench Formation, older, non-mare basalts enriched in KREEP (potassium K, rare-earth elements REE, and phosphorous P). The ABF is complex, with ejecta from Archimedes roughening it's surface, which is cut by a family of mostly narrow rilles vaguely radial to the center of Imbrium. The Archimedes Mountains are old hills that curve slightly toward the center of the Imbrium Basin - are they a collapsed part of the Apennine Mountains, or remnants of a large old crater, or parts of an inner ring of the basin? I am surprised that the upper (southwest) end of the Archimedes Mountains doesn't gradually lower, with peaks sticking through Mare Imbrium. The mountains seem to be part of the ABF, not just accidentally associated with it. Explore more of this great image.